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Entered, according to the Act of Congress, in the year 1832, by


In the Clerk's office of the District Court of the Eastern District of Pennsylvania.

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AE E55 1835 V.10



PEN, WRITING-PENS. It is well known that the ancients employed a certain reed, the nature of which is not precisely ascertained, for writing. The reeds were split, and shaped to a point like our quills. When goose-quills first came into use, or who first borrowed from the emblem of folly the instruments of wisdom, is not known. It has been asserted, that quills were used for writing as early as the fifth century, according to the history of Constantius. The oldest certain account is a passage of Isidore, who died 636 A. D., and who, among the instruments employed for writing, mentions reeds and feathers. There exists, also, a poem on a pen, written in the same century, and to be found in the works of Adhelm, the first Saxon who wrote in Latin. Alcuin (q. v.), the friend and teacher of Charlemagne, mentions writing-pens in the eighth century. After that time, proofs exist which put the question of their use beyond dispute. Mabillon (q. v.) saw a manuscript gospel of the ninth century, in which the evangelists were represented with pens in their hands. Calami properly signify the reeds which the ancients used in writing. Modern authors often use the word as a Latin term for pens, and it is probable that the same was employed to signify quills before the time of Isidore. Reeds were used for a considerable time after the introduction of writing-pens. In convents they were retained a long time for the initials only. By some letters of Erasmus to Reuchlin, it appears that the former received three reeds from the latter, and expressed a wish that Reuchlin, when he procured more, would send some of them to a certain learned man in England. Quills, for some reason, were, about the

year 1433, extremely rare in Venice. We learn from the familiar letters of learned men of that time, that they were equally troubled by the rarity of quills and by the difficulty of making good ink. Of late, steel pens have been much used and improved, and for certain purposes, as for signing bank notes, to make the signatures uniform, they appear well adapted; as also for people who cannot make pens; but, on the whole, the quill affords a much easier and handsomer chirography.

PENAL LAW. (See Criminal Law.) PENANCE; every penalty borne for the expiation of an offence. In the early Christian church, this ancient judicial principle was transferred to religious penance, that is, to the atonement which the sinner has to make, for his trespasses, to God and the church. According to the doctrine of the Protestants, it is not among the sacraments. This doctrine considers compunction and faith as the only elements of repentance and reformation. Penance is considered by the Catholic church a sacramental institution. The conditions for the necessary transition from bad to good, are a humble consciousness of guilt. The conversion itself is a change in the soul of man, effected by the power of God, but necessarily connected with an exterior alteration. The power of forgiving sins, in the literal sense of the word, say the Catholics, has been transferred by Christ to the apostles, and to the church; but the latter can forgive the sins only of the truly repentant and converted sinner. To bring him to the knowledge of himself, the church has established confession; to calm his conscience, absolution; for the instruction and discipline of the converted, she in

flicts penance, as a satisfaction to his own conscience and to God. Confession was not invented by Innocent III, but only enjoined by him at least once a year. It is followed by absolution, according to the authority transmitted to the church, and by the imposition of such penances as are necessary to free from the consequences of sin. The council of Trent declares, in sess. xiv, c. 8, that satisfaction for sin is effected only by Christ, and it is left for the individual to bring forth fruits worthy of repentance. Days of penance and fasting are holy days, which, in certain countries, are fixed annually, or after general calamities, for the purpose of a general expression of penitence, or with the view of appeasing the anger of the Deity. The great day of fasting among the Jews is the Long Night. The Christians imitated these fast-days.

PENATES; the private or public gods of the Romans; in the former sense, they resembled the Lares (q.v.), with whom they are often confounded. Not only every house, but every city, had its Penates, and the latter were the public gods. The most celebrated at Rome were those that protected the empire. These were brought into Italy by Æneas, together with Vesta and her eternal fire. According to Varro and Macrobius, the Penates were rude images of wood or stone,furnished with a spear; and generals, on their departure, and consuls, pretors and dictators, when they retired from office, sacrificed victims before them. PENCIL; an instrument used by painters for laying on their colors. Pencils are of various kinds, and made of various materials; the larger sorts are made of boar's bristles, the thick ends of which are bound to a stick, large or sinall, according to the uses they are designed for; these, when large, are called brushes. The finer sorts of pencils are made of camels', badgers' and squirrels' hair, and of the down of swans; these are tied at the upper end with a piece of strong thread, and enclosed in the barrel of a quill. Good pencils, when drawn between the lips, come to a fine point.

Lead Pencils. (See Plumbago.)

Pencil of Rays; a number of rays diverging from some luminous point, which, after passing through a lens, converge again to a point.

PENDANT. Two paintings or prints of equal dimensions, which are attached in corresponding positions to the same wall, are called pendants to each other.

PENDANT, OF PENNANT; a sort of long narrow banner displayed from the mast

head of a ship-of-war, and usually terminating in two ends or points, called the swallow's-tail. It denotes that a vessel is in actual service.-Broad pendant is a kind of flag terminating in one or two points, used to distinguish the chief of a squadron.-Pendant is also a short piece of rope, fixed on each side, under the shrouds, upon the heads of the main and fore masts.

PENDULUM, in dynamics, is a simple ponderous body, so suspended by a flexible cord from an axis of suspension, that it is at liberty to vibrate by the action of its own gravity alone, when it is once raised, by any external force, to the right or left of its quiescent position; and, in demonstrating the theory of its motion, mathematicians are obliged to assume, that there is no rigidity in the cord, no friction at the axis of suspension, no resistance to motion made by the air, and no variation in the total length of the cord, arising from the variable temperature or moisture of the atmosphere; and if these assumptions were strictly correct, a pendulum, once put in motion, would continue to move, ad infinitum, without a further accession of any external force; but, when the pendulum is applied as the regulator of a clock, for which purpose it is admirably adapted, the assumptions which we have stated, require an equal number of mechanical corrections, of which the theory, simply considered, takes no notice. In horology, therefore, the pendulum must be considered not simply as a self-moving pendulous body, without any tendency to come to a state of rest, but as a body whose motion is perpetuated by repeated accessions of force in aid of its own gravity, and whose vibrations are rendered isochronal by a nice adaptation of mechanical contrivances, that prevent or remedy the influence of all natural impediments to uniform and uninterrupted motion. The first kind of pendulum (the theoretical) is called a mathematical or simple pendulum, the other the physical or compound pendulum. In the mathematical pendulum, the matter of the pendulous ball or bob is supposed to be collected into one point, so that the centres of gravity and of oscillation coincide. The doctrine of the pendulum is of the highest importance, but, as it cannot be fully developed without the aid of mathematics, nor rendered clear without diagrams, we can state only some of the most obvious properties and circumstances connected with it. A pendulum, once put in motion, would never cease to

oscillate in arcs, were it not for the fric-basis for a calculation of the length of the tion at the point of suspension, and the degrees in the various latitudes; but acturesistance of the air. Neither of these al measurements have shown that the circumstances can ever be avoided en- meridians contain some irregularities, from tirely, but their effect may be rendered which it has been justly concluded, that comparatively slight by giving to the the earth has not a perfectly regular form, weight a lenticular shape, and suspending but deviates more or less from the shape the rod on a sharp edge, on which it of a sphere. We can, therefore, properly plays with very little friction. The times draw conclusions from the oscillations of of the vibrations of a pendulum depend, the pendulum respecting the power of 1. on the magnitude of the angle of elon- gravity only, and not respecting the form gation, viz. that angle by which the heavy of the earth. Besides the friction of the body of the pendulum is removed from rod, &c., and the resistance of the air, the vertical line; 2. upon the length of there are also other circumstances which the pendulum; and 3. upon the accele- influence the oscillations of the pendulum. rating power of gravity. If all these cir- These are the changes of heat and cold. cumstances are perfectly equal in the case Heat lengthens the rod of the pendulum, of two pendulums, they will perform an cold contracts it; hence common pendulum equal number of oscillations in the same clocks go much quicker in winter; and the time; but if there is a difference in either change of temperature in rooms which are of the circumstances, the oscillations will heated during the day influences them condiffer immediately. Thus, if one pendu- siderably. Many contrivances have been lum is shorter than the other, and all the devised for overcoming this inconvenience. other circumstances equal, the shorter One is, by making pendulums of the form pendulum will move quicker than the of a gridiron, consisting of several parallel longer. The law which has been found bars of different metals, so connected that to exist is, that the lengths of the pendu- the effect of one set of them counteracts lumns are in an inverse proportion to the that of the others. These have been squares of their oscillations; hence the very successful. Rods are sometimes times of the oscillations are inversely as made of certain kinds of wood, well seathe square roots of the lengths of the pen- soned, which are little influenced by the dulums. Hence a pendulum which is weather. Astronomical clocks of the four times as long as another, will vibrate present day do not err to the amount of with but half the rapidity, or the shorter one beat or oscillation of the pendulum in pendulum will perform two oscillations a year. A common clock is merely a whilst the larger performs but one. The pendulum with wheel-work attached to it, pendulum does not perform its oscillations to record the number of vibrations, and in equal times in all parts of the earth. with a weight or spring to counteract the This is owing to the third of the circum- retarding effects of friction and the resiststances enumerated above, upon which ance of the air. Huygens, who developed the oscillations depend. The gravity, or, the doctrine of the pendulum, which had what is the same thing, the power of at- been treated already by Galileo, first aptraction in the earth, does not operate ev- plied it to clocks, and thus became the ery where with equal force on the pendu- inventor of the pendulum clock (in 1656). lum, which, therefore, in some parts of the (See Clock.)-For the application of penearth, oscillates more slowly than in others. dulums to horology, see Berthoud's The cause of this lies in the centrifugal Essai sur l'Horlogerie (Paris, 1763, 2 force (q. v.), or in the diminution of the vols., 4to.).-See, also, Biot's treatise Sur la power of gravity caused by it. This be- Longueur du Pendule à Secondes, in the comes more perceptible the nearer the third volume of his Traité d'Astronomie place where the pendulum is observed Physique (second edition, Paris, 1810).--is to the equator. (See Earth.) At See, also, Bode's Anleitung zur Kenntniss the equator, therefore, a pendulum vi- der Erdkugel (second edition, Berlin, 1803). brating seconds must be somewhat shorter PENELOPE. (See Ulysses.) than at a distance from it. The length PENGUIN. (See Pinguin.) of a seconds pendulum at the equator is, PENITENTIARIES. (See Prisons.) according to Biot, 39.011684 inches; in latitude 45°, 39.116820, in 90°, 39.221956. If the globe were a perfect spheroid, the meridians would be perfect ellipses, and in such case the length of seconds pendulums would immediately afford a

PENN, William, was born in London, in 1644. He was the only son of William Penn, of the county of Wilts, vice-admiral of England in the time of Cromwell, and afterwards knighted by king Charles II, for his successful services against the

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